This invention relates generally to the field of automobiles, and in particular, to a system and method of providing optimal fuel economy for automobiles by automatically adjusting the operation of the powertrain based on the driving habits of the driver.
Pollutants generated by automobiles, and their effect on the environment, has been and continues to be an important public policy issue. In fact, stringent emissions requirements have been enacted by the Environmental Protection Agency (EPA) to force automobile manufacturers to increase the fuel economy and thereby reduce emissions generate by their automobiles. For example, the EPA requires all automobile manufacturers to comply with its Corporate Average Fuel Economy (C.A.F.E.) standard. Also, manufacturers are required to disclose to the public the fuel economy rating for each of its automobiles as governed by the Society of Automotive Engineers (SAE) Federal Test Procedure (FTP).
As the number of automobiles on the roadways continues to increase in the future, emissions standards will become even more stringent. As a result, automobile manufactures have been continuously attempting to increase fuel efficiency and reduce emissions of their automobiles. Automobile manufacturers have traditionally attempted to accomplish this by utilizing lighter materials such as, for example, aluminum instead of steel. They also have attempted to design and build higher efficiency engines and improved catalytic converters. However, these traditional approaches to improved fuel economy and reduced emissions each require significant development costs which in turn increases the overall cost of the vehicle considerably. Moreover, the significant investment that is typically required for improved engines, catalytic converters, and lightweight materials only provide marginal returns in terms of improving efficiency and lowering emissions.
Automobile manufacturers have also attempted to increase the fuel economy of conventional vehicles by implementing a shift schedule for the transmission that provides the most desirable blend of performance and fuel economy. However, conventional control algorithms used to generate the shift schedule for a particular vehicle is xe2x80x9cfixedxe2x80x9d by the manufacturer in manner that optimizes fuel economy and emissions for a given FTP test schedule. As a result, there is no way for these conventional control algorithms to adapt to the specific driving habits of a particular driver. The shift schedule therefore cannot be modified to match the driving habits of a particular driver to maximize the fuel economy for that particular driver. For example, the fuel economy for a vehicle cannot be maximized if the driver happens to be more aggressive than the programmed shift schedule set by the manufacturer, who usually sets the shift schedule to maximize fuel economy pursuant to a given FTP test schedule.
Accordingly, it would be desirable to have a system and method for optimizing the fuel economy for automobiles that overcomes the disadvantages described above under all types of driving conditions.
One aspect of the invention provides a method of optimizing fuel economy for an automobile. Driver torque request input data is received and is accumulated over a period of time to generate accumulated torque request data. Relevant or significant torque data is extracted from the accumulated torque request data. The relevant or significant torque data is processed to generate driver habit data from the torque data. The driver habit data is used to optimize fuel economy. A second driver torque request input data may preferably be received, and the driver habit data may be combined with the second driver torque input data to generate powertrain commands to optimize fuel economy. The driver torque request input data may preferably include an accelerator and brake torque request data. An accelerator and brake torque request history may preferably be determined. A rate of change of torque may also be determined. The driver torque request input data may preferably be accumulated over a period of thirty seconds or other predetermined period of time. A running average of torque may preferably be determined, and a torque histogram may preferably be generated. A slope of the torque histogram may preferably be determined. The habit data may preferably be stored as a preset for a particular driver. A driver identification may preferably be received. The powertrain commands for a conventional automobile may preferably include transmission commands and engine commands. The powertrain commands for a hybrid-electric vehicle may preferably include transmission commands, engine commands, and electric motor commands. A transmission including a plurality of gears may preferably be provided, and an optimal gear from the plurality of gears for the transmission may preferably be determined. An engine may preferably be provided, and an optimal torque for the engine may preferably be determined. An engine and an electric drive may be provided. In the context of a hybrid-electric automobile, an optimal torque for the engine and for the electric drive may preferably be determined. An optimal shift schedule may preferably be determined along with a battery charging torque for the engine. On/Off times for the engine may also be determined. An accelerator pedal may preferably be depressed to create the driver acceleration torque request input data.
Another aspect of the invention provides a system for optimizing fuel economy of an automobile. Computer readable program code receives driver torque request input data and accumulates the driver torque request input data to generate accumulated torque request data. Computer readable program code extracts relevant or significant torque data from the accumulated torque request data and processes the torque data to generate driver habit data from the torque data. Computer readable program code stores the driver habit data to optimize fuel economy. Computer readable program code may also preferably receive a second driver torque request input data and combine the driver habit data with the second driver torque request input data to generate powertrain commands to optimize fuel economy.
Another aspect of the invention provides a program for optimizing fuel economy of an automobile. Computer readable program code receives driver torque request input data and accumulates the driver torque request input data to generate accumulated torque request data. Computer readable program code extracts relevant or significant torque data from the accumulated torque request data and processes the relevant or significant torque data to generate driver habit data from the torque data. Computer readable program code stores and uses the driver habit data to optimize fuel economy. Computer readable program code may preferably receive a second driver torque request input data and may preferably combine the driver habit data with the second driver torque request input data to generate powertrain commands to optimize fuel economy and reduce emissions.
The invention provides the foregoing and other features, and the advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention and do not limit the scope of the invention, which is defined by the appended claims and equivalents thereof.